Regarding the SRAM Dual Drive, I have tuned the click-box already and the bike seems to be shifting correctly on the repair stand.
I noticed that at gear 1 (Downhill) the sound is pretty fine but when I shift to gear 2 (Flat) or 3 (Uphill) there is a noticeable but constant "clicker" sound.

Is this a normal internal hub characteristic or should I be worried?